Snow vehicle

ABSTRACT

A snow vehicle is disclosed comprising a vehicle frame, a propulsion unit coupled to the frame, and a front ski steered by a steering mechanism. The snow vehicle has a chain coupling the sprocket of the propulsion unit and a chain tensioning device to take up the chain tension. The chain has a chain guide positioned below a lower run of the chain which directs the chain towards an upper run of the chain.

BACKGROUND

The present disclosure relates to snow vehicles including snowmobilesand or snow bikes.

Many types of vehicles are configured with tracks to drive in the snow.Regardless of whether the vehicle is a snowmobile or a wheeled vehicleconverted to a tracked vehicle, tracked vehicles typically include adrive shaft mounted to a suspension system that supports the endlesstrack. The drive shaft typically includes drive sprockets that engagethe endless track. In the case of snow bikes, it is common that a motorbike is converted by removing the front tire and replacing it with aski, and by removing the rear tire and replacing it with a rearsuspension having a drive belt. Thus it is advantageous if thetransition from the motor bike to the snow bike is made as easy aspossible.

One such snow vehicle is shown in our U.S. Pat. No. 8,910,738, thesubject matter of which is incorporated herein by reference. This patentdiscloses a conversion of a motorbike into a snow vehicle where themotorbike powertrain is utilized to power the track of the convertedsnow vehicle. Other such snow bikes are known from our U.S. patentapplications, namely: Publications 2015/0144412; 2015/0259032;2016/0280331 and application Ser. Nos. 14/935,224; 14/935,265 and15/165,862; the subject matter of which are incorporated herein byreference.

SUMMARY

In a first embodiment, a rear suspension is provided for a snow vehiclehaving a vehicle frame and a propulsion drive member for driving thebelt. The rear suspension comprises a rear suspension frame; a drivebelt coupled to the rear suspension frame; a propulsion driven membersupported by the rear suspension frame; a linear element coupling thepropulsion drive member and the propulsion driven member to drive thedrive belt; a coupler for mounting to the rear suspension frame and forcoupling the rear suspension frame to the vehicle frame; a fasteningassembly for fixing the coupler relative to the rear suspension frame;and a linear assist member for assisting the movement of the couplerrelative to the rear suspension. When the coupler is fixed relative tothe rear suspension frame, the propulsion drive member and propulsiondriven member are fixed relative to each other, and when the fasteningassembly allows relative movement of the rear suspension frame and thevehicle frame, the linear assist member may be activated to move thepropulsion drive member and propulsion driven member relative to eachother, to tighten the linear element.

In another embodiment, a rear suspension is provided for a snow vehiclehaving a vehicle frame and a propulsion drive member for driving thebelt. The rear suspension comprises a rear suspension frame having afront receiving area extending along a generally horizontal plane; adrive belt coupled to the rear suspension frame; a coupler for mountingto the rear suspension frame and coupling the rear suspension frame tothe vehicle frame, the coupler having a generally rectangular bodyportion which extends in a generally horizontal plane and which isreceivable in the front receiving area; a fastening assembly for fixingthe coupler relative to the rear suspension frame.

In another embodiment, a kit is provided for converting a motor bikeinto a snow bike, where the motor bile has a bike frame and a propulsionmember. The kit comprises a rear suspension having a suspension frameand a drive belt coupled to the rear suspension frame, the drive beltbeing coupled to the suspension member and having a belt width; and afront ski coupled to a steering mechanism of the motor bike, the frontski having a ski width. The ski width is equal to or greater than thebelt width.

In yet another embodiment, a rear suspension is provided for a snowvehicle having a vehicle frame and a propulsion drive member for drivingthe belt. The rear suspension comprises a rear suspension frame; a drivebelt coupled to the rear suspension frame; a propulsion driven membersupported by the rear suspension frame; a linear element coupling thepropulsion drive member and the propulsion driven member to drive thedrive belt; and a brake mechanism coupled to the propulsion drivenmember and having a cover substantially surrounding the brake mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in relation to the drawing figureswhere:

FIG. 1 is a side view of the snow vehicle as disclosed in the presentdisclosure;

FIG. 2 shows a left front perspective view of the rear suspension;

FIG. 2A is an enlarged portion of the front frame shown in FIG. 2;

FIG. 3 shows a right front perspective view of the rear suspension;

FIG. 4 shows a left front underside perspective view of the rearsuspension;

FIG. 5 shows a right front underside perspective view of the rearsuspension;

FIG. 6 shows a left hand side view of the rear suspension;

FIG. 7 shows a left front perspective view of the rear suspension;

FIG. 8 is an enlarged portion of the area denoted in FIG. 7;

FIG. 9 shows a top view of a narrow track frame;

FIG. 10 shows a top view of a wide track frame;

FIG. 11 shows a short spool for use in assembling the narrow track frameof FIG. 9;

FIG. 12 shows a long spool for use in assembling the wide track frame ofFIG. 10;

FIG. 13 shows a top perspective view of the chain tensioning mechanism;

FIG. 14 is an enlarged portion of the area denoted in FIG. 13;

FIG. 15 is a top perspective view of the forged coupler shown in FIG.13;

FIG. 16 is an underside perspective view of the forged coupler shown inFIG. 13;

FIG. 17A is a view similar to that shown in FIG. 13, showing the leftspine member exploded away from the forged coupler, with the forgedcoupler in a fully retracted position;

FIG. 17B is a view similar to that shown in FIG. 17A, with the forgedcoupler in a fully extended position;

FIG. 18 is a side view of the shock absorber coupled between the motorbike frame and rear suspension;

FIG. 19 is an enlarged front perspective view of the front of the snowbike showing the chain input drive, chain casing and belt drive;

FIG. 20 is a side view of the snow bike showing a front of the snow bikepartially broken away to show the chain drive;

FIG. 21 shows an enlarged perspective view of the chain guide withoutthe chain;

FIG. 22 shows an enlarged perspective view of the chain guide;

FIG. 23 shows an enlarged perspective view of the brake mounted withinthe frame;

FIG. 24 shows an enlarged perspective view of the brake without theouter casing;

FIG. 25 shows an exploded view of the brake assembly;

FIG. 26 shows a front left perspective view of a portion of the drivebelt;

FIG. 27 shows a cross-sectional view through lines 27-27 of FIG. 26;

FIG. 28 is a front left perspective view of the front ski; and

FIG. 29 is an underside perspective view of the ski of FIG. 28.

DETAILED DESCRIPTION OF THE EMBODIMENTS

With reference first to FIG. 1, a snow vehicle is shown generally at 2as comprised of a motorcycle portion 4 having a propulsion unit 6, whichis shown as a two-cylinder motorcycle engine, a frame 8, an operatorsseat 10, and a steering assembly 12 which includes a front fork 14. Arear suspension assembly 20 is shown having an upper frame portion 22,slide rails 24, side panels 26, control arms 28, 30, linear forceelements 32 and 34 (shown diagrammatically in FIG. 6 as shock absorbers)and an endless belt or drive track 36.

With reference now to FIGS. 2-6, rear suspension 20 will be described ingreater detail. With reference first to FIG. 2, rear suspension 20includes a modular frame portion 40, a front coupler 42, and a chaintransfer case 44 which couples track drive 46 to an input chain drive48. Rear suspension 20 also includes a linear assist member or chaintensioning mechanism 50 as further described herein. Modular frameportion 40 includes side panels 26 which are defined as a first sidewall or left-hand plate portion 52 and a second side wall or right-handplate portion 54 which extend a substantial length of the modular frame40. As shown best in FIG. 2A, center spine portions include a left-handspine portion 56 and a right-hand spine portion 58 where spine portions56, 58 are spaced apart by a front spacer 60, a middle spacer 62 and arear spacer 64. Meanwhile, plate portions 52 and 54 are spaced apartfrom spine portions 56, 58 by way of a front spacer 70, middle spacer 72and rear spacer 74. Spacer 60 and 64 are hourglass-shaped in crosssection (See FIG. 17A) having apertures 80 and 82. Thus, one fastener 84(FIG. 2A) can be positioned through the front side of spacer 64 tocouple the spine portions 56 and 58 together, while fasteners 86, 88 and90 couple the outer plates 52, 54 to the center spines 56, 58 (FIG. 2A).

Namely, fastc ener 86 is positioned through plate portion 52, throughthe left-hand side spacer 70, through spine portion 56, through spacer60, through right-hand side spacer 70, and through plate 54 to receive afastener 92 (FIG. 3). In a like manner, fastener 88 is positionedthrough plate portion 52, through left-hand side spacer 72, throughspacer 62, through right-hand side spacer 72, and through plate portion54 to receive a fastener 94 (FIG. 3). Finally, fastener 90 can bepositioned through plate portion 52, through left-hand side spacer 74,through spacer 64, through right-hand side spacer 74, through plateportion 54 to receive the fastener 96 (FIG. 3). It should be appreciatedthat the fasteners 86, 88 and 90 could be elongated bolts whereasfasteners 92, 94 and 96 are nuts which thread on the end of bolts 86, 88and 90; alternatively all of fasteners 86, 88, 90, 92, 94 and 96 couldbe bolts where the spacers 60, 62 and 64 are internally threaded toreceive the aforementioned bolts.

As shown best in FIGS. 3-5, the rear of upper frame portion 40 includesa rear spacer 100 having fastener 102 (FIG. 4) and fastener 104 (FIG. 3)to couple plate portions 52, 54 together and spaced apart by spacer 100.A tunnel portion 110 is defined by a plate or upper panel 112 whichcouples to spacer 100 at a rear portion 114 by way of fasteners 116.Plate portion 112 includes folded-over side edges 120 (FIG. 5) and 122(FIG. 4) which couple to plate portions 52, 54 by way of fasteners 130(FIG. 4) and 132 (FIG. 5).

With the design of the upper frame portion 40 as described above, themodular design provides for an easy approach to accommodate multipleframe widths. With reference to FIGS. 7-11, spacer 74 is shown ingreater detail. As shown, spacer 74 is somewhat spool-shaped having acenter portion 140 and embossed ends 142 having an aperture 143therethrough. With reference to FIG. 9, spacer 74 is a narrow spacersuch that the width of the upper frame portion 40 is also narrow. Asshown in FIG. 12, an elongate spacer 74′ is shown. This yields a widerframe upper portion 40′ by including longer spacers 70′, 72′ and 74′,and an elongate end portion 100′ and tunnel plate portion 112′, as shownin FIG. 10.

With reference now to FIGS. 13-17B, front coupler 42 and chaintensioning mechanism 50 will be described in greater detail. Withreference first to FIG. 15, front coupler 42 is shown as a forgedcoupler including a base portion 150 having side walls 152, 154 and anend wall 156. The base portion 150 has a hollowed out section 158defining a through passage way at 160 and hollow well portions 162. Athreaded aperture 164 extends through the rear wall 156 and into thehollow portion 158. Wells 162 include a threaded aperture at 166 whichwill be described in greater detail herein. Side walls 152 and 154include front slotted apertures 170 therethrough and rear slottedapertures 172. A yoke 180 extends forwardly from the base portion 150including two yoke arms 182 having apertures at 184. As shown best inFIG. 13, forged coupler 42 is received in a front end of spine portions56 and 58 such that apertures 184 (FIG. 15) project forwardly andprovide the coupling to the frame of the motorbike frame.

With reference now to FIGS. 13, 14, 17A and 17B, the chain tensioningmechanism 50 will be described in greater detail. With reference firstto FIG. 17A, a front end of spine portions 56 and 58 is shown, whereeach front end includes a channel-shaped portion 200 defined by an upperwall portion 202 and a lower wall portion 204 defining a channel 206therebetween. It should be appreciated that in FIG. 17A, spine portion56 is spaced apart from its normal location, having been removed fromspacer 64 to show the clarity of the forged coupler 42 in thechannel-shaped portion of spine portion 58. Channel-shaped portion 200further includes an aperture 210 which aligns with aperture 80 in spacer64 and an aperture 212 which aligns with aperture 82 in spacer 64.Channel-shaped portion 200 further includes a front aperture 214 whichgenerally aligns with slot 170 and an aperture 216 which generallyaligns with slot 172. As shown in FIGS. 13 and 17A, a fastener 220 ispositioned through apertures 214 of spine portions 56, 58 and throughslotted portion 170. In a like manner, fastener 222 extends throughapertures 216 of spine portions 56 and 58 and through slot 172. Afastener plate 230 is provided having nuts 232 positioned inspaced-apart manner to align with apertures 214 and 216. As disclosed,nuts 232 are welded to fastener plate 230. This provides an easyone-person operation, as only the fasteners 220, 222 (FIG. 17A) requirea tool to loosen them.

Thus, this design allows for simple chain tensioning adjustment. Whenfasteners 220 and 222 extend through corresponding apertures 214 and216, fastening plate 230 can be positioned against apertures 214 and216, and fasteners 220, 222 can be threadibly received in nuts 232. Itshould be appreciated from viewing FIG. 17A that forged coupler 42 is inits rearward-most or retracted position where a front edge of slot 170is pushed against fastener 220 and where a front edge of slot 172 ispushed against fastener 222. Thus, forged coupler 42 may be held inposition trapped in between the spine portions 56 and 58 and moreparticularly, in the channel-shaped portions 200 of each of the spineportions 56, 58.

With reference now to FIG. 14, a jack bolt 240 is provided which isthreadibly received in threaded aperture 164 (FIG. 15) and includes athreaded shank at 242, a head 244 and a lock nut is provided at 246. Itshould also be appreciated from FIG. 14, that end wall 156 is curvedthereby providing a spacing between end wall 156 and spacer 64. Thisallows the head 244 and lock nut 246 to be positioned between the endwall 156 and spacer 64. Thus, chain tensioning is provided in a verysimple operation by loosening fasteners 220 and 222 which allow forgedcoupler 42 to move relative to spine portions 56, 58. As jack bolt 240is centrally located between spine portions 56, 58, retracting jack bolt240 that is, turning head 244 in a counter-clockwise position, wouldcause head 244 to abut spacer 64. Continued turning of head 244 in acounter clockwise direction moves forged coupler 42 and upper frameportion 40 relative to each other. Thus, this provides chain tensioningwith the chain drive 48 whereby lock nut 246 can be moved in a clockwiseposition tightening the lock nut against end wall 156 locking the jackbolt 240 in its position. As shown in FIG. 17B, forged coupler 42 is inits forward-most or extended position where a rear edge of slot 170 ispulled against fastener 220 and where a rear edge of slot 172 is pulledagainst fastener 222.

With reference now to FIGS. 19 and 20 the routing of the chain drivewill be described in greater detail. As shown best in FIG. 19, spine 56includes a raised portion 250 which allows mounting of flange 252 whichin turn mounts sprocket 254 thereto. Sprocket 254 receives power fromthe motor bike from the output sprocket 256 (see FIG. 20). As shown bestin FIG. 20, a linear element 260 in the form of a chain is routed aroundsprocket 254 driven by sprocket 256 and positioned over a top of chainguide 266. As shown best in FIG. 22, chain guide 266 includes a U-shapedaperture 268 such that chain guide 266 is received over spacer 70. Chainguide 266 further includes an arcuate surface 270 having a central rib272 extending therealong. As shown best in FIGS. 5 and 13, a secondchain guide 274 is positioned on the left hand side yoke arm 182, andhas a rib 276 which aligns with rib 272 for contacting the chain 260.Thus, rib 272 can be positioned intermediate chain links to guide thechain up and away from the belt 36 as shown best in FIG. 20. As shown inFIG. 20, chain guide is positioned on the outside of chain 260 pushingchain 260 upwardly towards the upper length of the chain 260. As shownbest in FIGS. 19 and 23, sprocket 254 drives chain transfer case 44which in turn drives sprockets 280 through shaft 282. Belt 36 isentrained around sprockets 280, slide rails 24 (FIG. 19), idler rolls284 and idler rollers 286 (FIG. 1).

As shown best in FIGS. 17A and 18, a shock absorber 300 is shown havinga body portion 302, an upper coupling 304 and a lower coupling 306. Asshown best in FIG. 17A, shock 300 is coupled within well 162 by waylower coupling 306. Lower coupling 306 includes adjustment linkage 310having threaded rod 312 and transverse rod 314. Threaded rod 312includes a jam nut 315, such that the length of shock 300 can beadjusted by loosening jam nut 315 and threading rod 312 into or out ofthe body portion 302. As best shown in FIG. 17A, transverse rod 314 hasapertures 316 which align with apertures 166, for receiving a fastenersuch as a bolt therethrough for retaining the lower coupling 306 withinthe forged coupling 42.

With reference now to FIGS. 23-25, brake assembly 320 will be describedin greater detail. As mentioned before, flange 252 is mounted to aportion 250 of spine 56 which mounts sprocket 254 thereto. Sprocket 254is coupled to a shaft 321 (shown in phantom in FIG. 23) which operates asprocket (not shown) within transfer case 44, but is also coupled to abrake disk 322 (FIG. 25) of brake assembly 320. As shown best in FIG.25, brake assembly 320 includes a caliper 324 having posts 326 withthreaded apertures 328. Flange 252 includes an outer flange portion 252a and an inner flange portion 252 b where the flange portions 252 a, 252b include apertures 252 c. Flange portions 252 a and 252 b also includeapertures 252 d. A bearing 340 is positioned between the flangedportions 352 a and 352 b. Fasteners 342 may be positioned throughapertures 252 c and received into threaded posts 326; and fastener 344may be positioned through apertures 252 d, trapping portion 250 of spine56 therebetween (FIG. 23). A washer 346 and fastener 348 are positionedon the backside of spine 56 and couple to faster 344.

It should be understood that shaft 321 also extends through flange 252and into splined portion 350 of brake disc 322. A spacer 352 ispositioned between bearing 340 and splined portion 350 and extends overshaft 321. As shown best in FIG. 24, disk 322 is positioned in a slot354 of caliper 324, and disk pads (not shown) contact disc 322 forbraking purposes. As also shown in FIG. 25, a cover surrounds brake disk322 and includes a cover portion 360 and cover portion 362. Coverportion 360 is coupled to cover portion 362 by way of fasteners 368extending through apertures 370 of cover portion 360 and into threadedengagement with threaded bosses 372 on cover portion 362. Cover portions360 and 362 are coupled to spine 56 by way of spacers 380 (see FIGS. 23and 25) and fasteners 382 extending through apertures 384 and coupled tothreaded bosses 386 (FIG. 25) on the back side of cover 372 to couple tospine 56.

With reference now to FIGS. 26 and 27, belt 36 will be described ingreater detail. As shown in FIG. 26, belt 36 includes a belt bodyportion 400 having outer track lugs 402 and inner lugs 404. As shownbest in FIG. 27, the distance between an outer edge 408 of the lugs 402has a width W₁, and the outer width of track body 400 has a width W₂. Inthe embodiment shown, W₂=11.5″ and W₁=11.25″ although W₂ could be10.75″. Thus, a ratio of W₁/W₂ has a value of 1.022 and is in the rangeof 1.0-1.070.

With reference now to FIGS. 28 and 29, a front ski assembly is shown at450, including a spindle portion 452 couple to a ski 454. Ski 454 issubstantially similar to that shown in our U.S. patent applicationpublication number 2015/0259032, incorporated herein by reference. Asshown, a distance between side edges 460 of ski 454 is W₃. In theembodiment shown, W₃ is equal to or greater than W₂ (width of belt asshown in FIG. 27), such that ski 454 flattens the snow for the trackbelt 36. In the embodiment shown, the width of the ski is 11.5″. Thusthe ratio W₃/W₂ is 1 to 1, but the ratio of W₃/W₂ has a range between 1to 1 and 1.5 to 1 (11.5″-17.25″ ski), and is preferably in the range 1to 1 and 1.3 to 1 (11.5″-14.95″ ski) and more preferably in the range of1 to 1 and 1.2 to 1 (11.5″-13.8″ ski).

As shown in FIGS. 9 and 19, the width of the chain transfer case 44 isvery narrow as compared to other previously known snow bikes. Thisprevents the transfer case 44 from dragging through the snow, causing adrag on the snow bike. As shown in FIG. 9, the nominal width of theframe 40 is W₄ and the total width of the rear suspension including thetransfer case is W₅. In the embodiment shown, W₄=12.375″ andW₅=13.8125″. The ratio of the total width to the frame 40 is W₅/W₄ andin the embodiment shown is 1.116 and has a range of 1.0-1.25, and ispreferably is in the range 1.10-1.2.

Also, as the mounting of the sprocket 254 is high in the frame 40, seeFIG. 19, the air box in the motor bike need not be moved which providesease of installation. Furthermore, since shock 300 is coupled to theforged coupler 42, rather than to the rear frame 40, the position andangle of the shock 300 never changes, even when the chain tensioningdevice 50 is used.

While this invention has been described as having an exemplary design,the present invention may be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

The invention claimed is:
 1. A kit for converting a motor bike into asnow bike, where the motor bike has a bike frame and a propulsionmember, the kit comprising: a rear suspension having a suspension frameand a drive belt coupled to the rear suspension frame, the drive beltbeing operably coupled to the suspension frame and having a belt width,and the suspension frame having a first side wall, a second side wall,and an upper panel extending between the first and second side wall todefine a tunnel, and the tunnel having a tunnel width configured toreceive the drive belt; and a front ski coupled to a steering mechanismof the motor bike, the front ski having a forward portion, a rearwardportion, and an intermediate portion extending generally longitudinallybetween the forward and rearward portions, and a ski width is defined asa lateral width of the intermediate portion, wherein the ratio of theski width to the belt width is in the range of 1/1 to 1.5/1.
 2. The kitof claim 1, wherein the front ski includes a forward extent, a rearwardextent and longitudinally-extending side edges extending therebetween,and the ski width is defined as the lateral width between thelongitudinally-extending side edges.
 3. The kit of claim 2, wherein theforward extent tapers towards a forward-most end of the front ski. 4.The kit of claim 2, wherein a width of the rearward extent of the frontski is approximately equal to the ski width.
 5. The kit of claim 2,further comprising a coupling assembly for coupling the front ski to thesteering mechanism, and the coupling assembly is positioned laterallyintermediate the longitudinally-extending side edges.
 6. The kit ofclaim 5, wherein the coupling assembly is positioned longitudinallyintermediate the forward extent and the rearward extent of the frontski.
 7. The kit of claim 1, wherein the ratio of the ski width to thebelt width is in the range of 1/1 to 1/3.
 8. The kit of claim 7, whereinthe ratio of the ski width to the belt width is in the range of 1/1 to1/2.
 9. The kit of claim 1, wherein the ski width is approximately 11.5inches to 17.25 inches.
 10. The kit of claim 1, wherein the rearsuspension defines a suspension width greater than the ski width. 11.The kit of claim 1, wherein the rear suspension defines a suspensionwidth less than the ski width.
 12. The kit of claim 1, wherein thelateral width of the intermediate portion defines a maximum ski width.13. The kit of claim 1, wherein the front ski is coupled to the steeringmechanism at the intermediate portion, and the lateral width of theintermediate portion defines a maximum ski width.
 14. A kit forconverting a motor bike into a snow bike, where the motor bike has abike frame and a propulsion member, the kit comprising: a rearsuspension having a suspension frame and a drive belt coupled to therear suspension frame, the drive belt being operably coupled to thesuspension frame and having a belt width, and the suspension framehaving a first side wall, a second side wall, and an upper panelextending between the first and second side wall to define a tunnel, andthe tunnel having a tunnel width configured to receive the drive belt,wherein the first and second side walls generally define the outermostextent of a rear portion of the snow bike; and a front ski coupled to asteering mechanism of the motor bike, the front ski having a ski widthdefined as a lateral extent of a mid-portion of the front ski, and theratio of the ski width to the belt width is in the range of 1/1 to1.5/1.
 15. The kit of claim 14, further comprising a coupling assemblyconfigured to operably couple the front ski to the steering mechanism,and the coupling assembly is positioned within the mid-portion of thefront ski.
 16. The kit of claim 14, wherein the front ski furtherincludes a forward end positioned forward of the mid-portion and arearward end positioned rearward of the mid-portion, and the forward endhas a width less than that of the ski width.
 17. The kit of claim 16,wherein the rearward end has a width at least equal to the ski width.18. The kit of claim 14, wherein the ratio of the ski width to the beltwidth is in the range of 1/1 to 1/3.
 19. The kit of claim 14, whereinthe ratio of the ski width to the belt width is in the range of 1/1 to1/2.
 20. The kit of claim 14, wherein the ski width is approximately11.5 inches to 17.25 inches.
 21. The kit of claim 14, wherein the skiwidth is approximately 11.5 inches to 14.95 inches.